Stream artifacts from content-app if using non-local filesystem storage

This commit removes the check against `REDIRECT_TO_OBJECT_STORAGE` from
the Registry handler that caused Pulp to stream content only when a user
opted for it. Now, the content is always streamed from content-app when
using non-local filesystem storage.

closes pulp#1493

CHANGES/1493.bugfix

@@ -0,0 +1,2 @@
+Fixed a bug that caused intermittent failures during the pull-through caching when using non-local
+filesystem storage.

pulp_container/app/registry.py

@@ -88,10 +88,8 @@ async def _dispatch(artifact, headers):
             if not os.path.exists(path):
                 raise Exception("Expected path '{}' is not found".format(path))
             return web.FileResponse(path, headers=full_headers)
-        elif not settings.REDIRECT_TO_OBJECT_STORAGE:
-            return ArtifactResponse(artifact=artifact, headers=headers)
         else:
-            raise NotImplementedError("Redirecting to this storage is not implemented.")
+            return ArtifactResponse(artifact=artifact, headers=headers)
 
     @RegistryContentCache(
         base_key=lambda req, cac: Registry.find_base_path_cached(req, cac),